Method of bolting together wooden members



July 18, 1950 B. LINDHAM METHOD 0F BOLTING TOGETHER WOODEN MEMBERS Filed Feb. 19, 1946 /m/'enor 6 RGER MoH/w www aorneys Patented July 18,950

METHOD OF BOLTING TOGETHER WOODEN MEMBERS Birger Lindham, Stockholm, Sweden, assignor to Olsson & Rosenlunds Aktiebolag, Stockholm,

Sweden Application February 19, 1946, Serial No. 648,662 In Sweden January 18, 1944 1 Claim.

The present invention relates to a method of bolting together the wooden members of a wood structure and consists in providing each of the wooden members with a through-hole, placing them one above the other while simultaneously inserting a friction washer between each two of the members in such manner that the holes of the wooden members and the apertures of the Washers are in alignment, placing the members tog-ether with the washers between a xed and a movable press pad, each press pad provided with a bore which is placed in alignment with the holes of the wooden members and apertures of the washers, inserting va centering rod through the bore of the fixed press pad, the holes of the members and apertures of the washers, the rod also extending into the bore of the movable press pad and a nut supported on a seat provided on the movable press pad, pressing the members together by the action of the movable press pad in such manner that the friction washers are pressed into the adjacent wooden members, removing the centering rod, inserting a bolt in exchange for the centering rod, screwing the free end of the bolt into said nut and iinally removing the wood structure now bolted together from said press pads.

An embodiment of an implement for carrying out the method according to the invention is shown in Figs. 1 and 2, of which Fig. 1 illustrates the implement in side view, and Fig. 2 the same in plan View.

The wood structure, which is to be bolted together, consists, as shown in Fig. l, ci a number of planks.

The implement according to Figs. l and 2 consists of a hydraulic clamp device and comprises a bow-shaped frame I5 in which there is arranged a traverse strengthening beam i6, which also serves to support a hydraulic lifting jack I 1 arranged at the lower part of the frame I5. The projecting lifting spindle I8 of the lifting jack is provided with an exchangeable press pad I9, which is provided with a central bore for receiving the lower end of a centering bar 29. The bore of the press pad I9 is provided with a seat for a nut 26 adapted to coact with the lower threaded end of the centering bar 29. The lifting piston of the lifting jack is actuated by means of th-e lever 2l. In order to make a coarse adjustment of the position of height of the press pad I9 the spindle I8 may be screwed in and out respectively in the lifting jack I'l in a manner known per se by means of a hand wheel 2li xed to the spindle.

I'he upper press pad 23, which is connected with the bow frame I5 by means of chains 22 adjustable as to their active length, consists of a beam provided with a central bore 25 for the centering bar 20.

After laying together the planks to press them together, the centering bar 20 is inserted through holes made previously in the planks, the intermediate friction members 21 having been applied between the planks and about the holes. Thereafter, preferably a washer 28 is put on the lower threaded end of the bar protruding from the lower plank, whereafter the nut 26 is threaded on and entered in the seat of the press pad I9.

The bore 25 is hereby so dimensioned that after the centering bar 20 has been removed after the pressing together of the planks, the final fixing bolt may be threaded into the nut arranged in the press pad I 9 by means of a socketwrench. By means of this it is gained that the nal fastening together by means of the fixing bolt may take place while the planks are still held pressed together by means of the hydraulic clamp device so that the xing bolt may not be exercised to any stronger lead than that normally required for maintaining the planks lastingly in the compressed position entirely by means of the hydraulic clamp device.

Having now particularly described the nature of my invention and the manner of its operation, what I claim is:

A method of bolting together the wooden members of a wood structure comprising the steps of providing a through-hole in each of said members, placing said members one above the other and inserting a friction washer between each two of said members in such manner that the holes of said members and the apertures of the washers are in alignment, placing said members together with said washers between a fixed and a movable press pad, each of said press pads being provided with a bore which is placed in alignment with the holes of said members and apertures of said washers, inserting a centering rod through the bores of the fixed press pad, the holes of the members and the apertures of said washers, said rod also extending into the bore of said movable press pad and a nut supported on a seat provided on said movable press pad,

pressing said members together by the action of said movable press pad in such manner that the friction washers are pressed into the adjacent wooden members, removing said centering rod, inserting a bolt in said holes, bores and apertures, screwing the free end of the bolt into said nut and finally removing the bolted wood structure from said press pads.

BIRGER LINDHAM.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date Peterson Dec. 7, 1909' Number Vetter June 13, 1944 

